Some medicaments presently available for treating glaucoma by lowering the intraocular pressure are not completely satisfactory because they are ineffective, and/or demonstrate unwanted cardio-vascular-pulmonary and CNS activities. Additionally, prior art compounds for this use plague the user with any one or more of the following side effects: obvious vasoconstricton or vasodilation of the vessels of the sclera; obvious pupil contraction or dilation; and painful stinging. Accordingly, there is a need in the art for compositions which are effective in lowering intraocular pressure and are devoid of unwanted side effects. Such freedom of side effects is particularly desired on topical administration to the eye.